1. Field of the Invention
The present invention relates to an air-bag arrangement. More specifically, the present invention relates to an air-bag arrangement for use in a motor vehicle such as an automobile.
2. Description of Related Art
There have been many proposals concerning air-bag arrangements to be utilized in motor vehicles, such as automobiles. In particular, it has been proposed to provide an air-bag arrangement in the form of an inflatable curtain that, when inflated, is located adjacent a driver or occupant of a vehicle, being positioned between the driver or occupant of the vehicle and the adjacent door or window opening.
Typically, an inflatable curtain of this type is initially stored within a housing or recess that follows a non-linear path across the top of the doorframe of the motor vehicle. The forward end of the recess or housing may extend down the xe2x80x9cAxe2x80x9d-Post of the motor vehicle, and the rear end of the recess or housing may extend partly down the xe2x80x9cCxe2x80x9d-Post or a post located to the rear of the xe2x80x9cCxe2x80x9d-Post.
In the event that an accident should occur, typically a side-impact or roll-over accident, the air-bag within the housing or recess is inflated, and the air-bag then forms a curtain extending parallel with the longitudinal axis of the vehicle. The curtain is substantially vertical and extends from the roof line, above the door or window opening, to a position located at the lower edge of the window opening or substantially in alignment with the center of the chest of the driver or occupant of the vehicle.
In many accident situations, the window glass is broken during the very first moments of the accident. Consequently, the inflatable curtain itself must have the necessary characteristics to retain the head, arms, and hands of the driver or occupant within the motor vehicle. Therefore, it is desirable for the lower-most region of such an inflatable curtain to be taut when the air-bag has been inflated, so that the complete side curtain constitutes a substantially rigid element that will prevent the head, arms, and hands of the driver or occupant of the vehicle from passing laterally outward through the window of the motor vehicle.
Various attempts have been made to develop a side curtain of this type that can be fabricated in such a way that when the side curtain is deployed, the lower-most region of the side curtain is substantially taut so that the curtain exhibits the desired characteristics.
One example proposes utilizing a strap that extends from the lower-most edge of the inflatable curtain, at a point adjacent one end of the inflatable curtain, to an anchoring point, for example on the xe2x80x9cAxe2x80x9d-Post of the motor vehicle. The strap in that example is inflatable so that the length of the strap may be reduced on deployment of the inflatable curtain. The length of the strap is such that the inflatable curtain, together with the strap in its fully extended condition, can be stored within the non-linear housing or recess that extends above the door opening and partway down the xe2x80x9cAxe2x80x9d-Post. However, on deployment of the inflatable curtain, the inflation of the strap causes the length of the strap to be reduced, thus enabling the strap to apply a tensioning force to one end of the inflatable curtain pulling the curtain taut. The inflatable curtain itself typically incorporates a plurality of separate cells that have axes that generally intersect the lower edge of the inflatable curtain so that, on inflation of the inflatable cells, the overall length of the lower-most edge of the inflatable curtain is reduced, thus enhancing the tensioning effect.
The use of an inflatable strap is undesirable, since it is relatively expensive to fabricate an inflatable strap, and, on deployment of the inflatable curtain, the inflation of the strap consumes gas that could more usefully be employed in inflating the inflatable part of the inflatable curtain.
According to the present invention, an air-bag arrangement is provided for use in a motor vehicle. The arrangement incorporates an inflatable element having an inflatable part and an edge part, connectors to secure the edge part of the inflatable element to a motor vehicle, and an inflator adapted to inflate the inflatable part of the inflatable element. The air-bag arrangement also incorporates a tether arrangement that includes a first and second tether of elongated form. The first tether has opposed ends secured to the inflatable element, such that the opposed ends may be adjacent each other when the inflatable element is un-inflated, and spaced apart when the inflatable element is inflated. The second tether has a first and second end. The first end associates with the first tether intermediate its ends. The second end is secured to the motor vehicle.
Preferably, the inflatable part of the inflatable element incorporates a plurality of discrete inflatable cells.
Additionally, it is preferable that the inflatable part of the inflatable element is initially in a folded condition such that the two opposed ends of the first tether are located adjacent one another.
Conveniently, one tether arrangement is provided adjacent one end of the air-bag arrangement.
An additional tether arrangement is optionally provided adjacent an opposing end of the air-bag arrangement.
Preferably, the air-bag arrangement is mounted within a motor vehicle. An edge part of the inflatable element and the second end of the second tether may be secured to the motor vehicle at points extending along a non-linear line located above an opening in the vehicle. The second end of the second tether is secured to a point located adjacent one end of the non-linear line.
Advantageously, when the inflatable element is inflated, a lower region of the inflatable element and the tethers are substantially taut and extend between two opposed ends of the non-linear line. The tautness in the inflatable element provides it with substantial rigidity, allows it to maintain its position if the adjacent windows break, and prevents the driver or occupant of the motor vehicle from passing through the opening in the vehicle.
Alternatively, the invention also provides an air-bag arrangement provided in a motor vehicle, the air-bag arrangement comprising a non-linear recess spanning at least one opening in the motor vehicle. The recess contains a tether arrangement and an initially folded inflatable element having one edge secured to said recess. The tether arrangement includes a first and second elongated tether. The first tether has opposed ends secured to the inflatable element, such that the opposed ends may be adjacent each other when the inflatable element is un-inflated and spaced apart when the inflatable element is inflated. The second tether has a first and second end. The first end of the second tether associates with the first tether intermediate its ends. The second end is secured to the motor vehicle at one end of the non-linear recess. The air-bag arrangement further includes an inflator adapted to inflate the inflatable part of the inflatable element. The arrangement is such that, on inflation of the inflatable element, a lower part of the inflatable element, substantially aligned with a line interconnecting two ends of the non-linear recess, is substantially taut.